The present invention relates to a cam device, for example, for driving a container sealing device or container filling device included in packaging machines.
Cam devices of the type mentioned and already known comprise a cam, a follower and an elastic means for causing the follower to follow the cam, the cam being a plate cam having an outer periphery serving as a cam contour face.
Cam devices are known which comprise a plate cam formed with an annular cam groove in one side surface thereof, and a follower having a roller attached thereto and fitting in the cam groove.
With the cam device of the former type, the elastic means needs to have a great elastic force for causing the follower to follow the cam without permitting the follower to move out of a contact with the cam contour face. To give such a great elastic force, the elastic means must be large or elaborate in construction, and driving the cam involves increased load variations, necessitating a greater drive source.
When the operative device to be driven by the latter cam device is to be operated, the follower is prevented from following the cam, and it has been impossible to bring the follower out of the following movement by a simple means.